5523 2007-12-27 19:25:00 +0000 Confusing warning: "expression dangerous with linker stubs" 2008-05-30 14:20:41 +0000 1 1 1 Unclassified binutils gas 2.18 All All RESOLVED FIXED P2 normal --- 1 j unassigned bug-binutils eric.weddington avr-*-* 20827 j 2007-12-27 19:25:58 +0000 This warning is emitted in line 648 of file gas/config/tc-avr.c. This warning has been confusing a lot of users in the past, because it is ultimately generated for legitimate assembly code generated by GCC as part of jump tables resulting out of a larger switch statement. Discussion with the author of the atmega256x patch, Björn Haase, resulted in an agreement that the warning should just be removed. There is indeed a minimal danger that a switch statement could cross an 128 KiB boundary where a linker stub could suddenly be placed within the table, but as the assembler cannot reliably detect this situation at all, it confuses more people with legitimate code (not crossing a 128 KiB boundary) than it would be really able to help out those who are in danger. In the end, the users are told to ignore the warning, so it doesn't do any good at all. In addition, Björn pointed out that it could only detect part of the problem but is not able to cover all possible dangerous cases, because some code might hide dangerous operations between other assembly code that is not covered by the warning. If at all, this warning needs to be emitted by GCC itself whenever it generates the possibly dangerous code. 20915 2177 nickc 2008-01-07 16:44:10 +0000 Created attachment 2177 Remove the warning 20916 nickc 2008-01-07 16:45:46 +0000 Hi Joerg, Please could you try out the uploaded patch and let me know if it resolves the problem for you ? Also - would it be possible for you to supply a small assembler source file that demonstrates this problem ? This could be turned in a gas test case to make sure that the problem remains fixed. Cheers Nick 23788 hutchinsonandy 2008-05-29 22:38:12 +0000 I applied this patch to Binutils-2.18.50 I ran full avr gcc testsuite and there were no regressions. Importantly, it removed all the failures caused by the warning message removed by this patch. So its get my vote! 23796 nickc 2008-05-30 14:20:41 +0000 Hi Guys, I have checked the patch in. Cheers Nick gas/ChangeLog PR 5523 * config/tc-avr.c (avr_ldi_expression): Do not warn about unknown relocs here. 2177 2008-01-07 16:44:00 +0000 2008-01-07 16:44:10 +0000 Remove the warning pr5523.tc-avr.c.patch text/plain 746 nickc SW5kZXg6IGdhcy9jb25maWcvdGMtYXZyLmMKPT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PQpSQ1MgZmlsZTogL2N2cy9zcmMv c3JjL2dhcy9jb25maWcvdGMtYXZyLmMsdgpyZXRyaWV2aW5nIHJldmlzaW9uIDEuNDgKZGlmZiAt YyAtMyAtcCAtcjEuNDggdGMtYXZyLmMKKioqIGdhcy9jb25maWcvdGMtYXZyLmMJMTYgTm92IDIw MDcgMTc6Mzk6MjIgLTAwMDAJMS40OAotLS0gZ2FzL2NvbmZpZy90Yy1hdnIuYwk3IEphbiAyMDA4 IDE2OjQzOjMwIC0wMDAwCioqKioqKioqKioqKioqKiBhdnJfbGRpX2V4cHJlc3Npb24gKGV4cHJl c3Npb25TICpleHApCioqKiA2MTgsNjI0ICoqKioKICAJCSAgICAgIGJyZWFrOwogIAogIAkJICAg IGRlZmF1bHQ6CiEgCQkgICAgICBhc193YXJuIChfKCJleHByZXNzaW9uIGRhbmdlcm91cyB3aXRo IGxpbmtlciBzdHVicyIpKTsKICAJCSAgICB9CiAgCQl9CiAgCSAgICAgIHJldHVybiByZWxvY190 b19yZXR1cm47Ci0tLSA2MTgsNjI2IC0tLS0KICAJCSAgICAgIGJyZWFrOwogIAogIAkJICAgIGRl ZmF1bHQ6CiEgCQkgICAgICAvKiBQUiA1NTIzOiBEbyBub3QgZ2VuZXJhdGUgYSB3YXJuaW5nIGhl cmUsCiEgCQkJIGxlZ2l0aW1hdGUgY29kZSBjYW4gdHJpZ2dlciB0aGlzIGNhc2UuICAqLwohIAkJ ICAgICAgYnJlYWs7CiAgCQkgICAgfQogIAkJfQogIAkgICAgICByZXR1cm4gcmVsb2NfdG9fcmV0 dXJuOwo=